android实现歌词自动滚动效果

最近在做android 的mp3播放的项目，要实现歌词的自动滚动，以及同步显示。

lyric的歌词解析主要用yoyoplayer里面的，显示部分参考了 ，这里只是模拟mp3歌词的滚动。

先上一下效果图：

滚动实现的代码其实也简单。显示画出当前时间点的歌词，然后再分别画出改歌词后面和前面的歌词，前面的部分往上推移，后面的部分往下推移，这样就保持了当前时间歌词在中间。

代码如下 lyricview，相关信息在注释了标明了。

package ru.org.piaozhiye.lyric; 
import java.io.file; 
import java.util.list; 
import android.content.context; 
import android.graphics.canvas; 
import android.graphics.color; 
import android.graphics.paint; 
import android.graphics.path; 
import android.graphics.typeface; 
import android.util.attributeset; 
import android.widget.textview; 
/** 
 * @author root 
 * 
 */ 
public class lyricview extends textview { 
 private paint mpaint; 
 private float mx; 
 private static lyric mlyric; 
 private paint mpathpaint; 
 public string test = "test"; 
 public int index = 0; 
 private list<sentence> list; 
 public float mtouchhistoryy; 
 private int my; 
 private long currentdunringtime; // 当前行歌词持续的时间，用该时间来sleep 
 private float middley;// y轴中间 
 private static final int dy = 50; // 每一行的间隔 
 public lyricview(context context) { 
 super(context); 
 init(); 
 } 
 public lyricview(context context, attributeset attr) { 
 super(context, attr); 
 init(); 
 } 
 public lyricview(context context, attributeset attr, int i) { 
 super(context, attr, i); 
 init(); 
 } 
 private void init() { 
 setfocusable(true); 
 playlistitem pli = new playlistitem("because of you", 
  "/sdcard/mp3/because of you.mp3", 0l, true); 
 mlyric = new lyric(new file("/sdcard/mp3/because of you.lrc"), pli); 
 list = mlyric.list; 
 // 非高亮部分 
 mpaint = new paint(); 
 mpaint.setantialias(true); 
 mpaint.settextsize(22); 
 mpaint.setcolor(color.white); 
 mpaint.settypeface(typeface.serif); 
 // 高亮部分 当前歌词 
 mpathpaint = new paint(); 
 mpathpaint.setantialias(true); 
 mpathpaint.setcolor(color.red); 
 mpathpaint.settextsize(22); 
 mpathpaint.settypeface(typeface.sans_serif); 
 } 
 protected void ondraw(canvas canvas) { 
 super.ondraw(canvas); 
 canvas.drawcolor(0xefeffff); 
 paint p = mpaint; 
 paint p2 = mpathpaint; 
 p.settextalign(paint.align.center); 
 if (index == -1) 
  return; 
 p2.settextalign(paint.align.center); 
 // 先画当前行，之后再画他的前面和后面，这样就保持当前行在中间的位置 
 canvas.drawtext(list.get(index).getcontent(), mx, middley, p2); 
 float tempy = middley; 
 // 画出本句之前的句子 
 for (int i = index - 1; i >= 0; i--) { 
  // sentence sen = list.get(i); 
  // 向上推移 
  tempy = tempy - dy; 
  if (tempy < 0) { 
  break; 
  } 
  canvas.drawtext(list.get(i).getcontent(), mx, tempy, p); 
  // canvas.translate(0, dy); 
 } 
 tempy = middley; 
 // 画出本句之后的句子 
 for (int i = index + 1; i < list.size(); i++) { 
  // 往下推移 
  tempy = tempy + dy; 
  if (tempy > my) { 
  break; 
  } 
  canvas.drawtext(list.get(i).getcontent(), mx, tempy, p); 
  // canvas.translate(0, dy); 
 } 
 } 
 protected void onsizechanged(int w, int h, int ow, int oh) { 
 super.onsizechanged(w, h, ow, oh); 
 mx = w * 0.5f; // remember the center of the screen 
 my = h; 
 middley = h * 0.5f; 
 } 
 // 
 /** 
 * @param time 
 *  当前歌词的时间轴 
 * 
 * @return currentdunringtime 歌词只需的时间 
 */ 
 public long updateindex(long time) { 
 // 歌词序号 
 index = mlyric.getnowsentenceindex(time); 
 if (index == -1) 
  return -1; 
 sentence sen = list.get(index); 
 // 返回歌词持续的时间，在这段时间内sleep 
 return currentdunringtime = sen.getduring(); 
 } 
} 

剩下的就是使用他了。就是取出歌词的index，和该行歌词持续的时间进行sleep。

package ru.org.piaozhiye; 
import java.io.ioexception; 
import ru.org.piaozhiye.lyric.lyricview; 
import android.app.activity; 
import android.media.mediaplayer; 
import android.os.bundle; 
import android.os.handler; 
public class lyricdemo extends activity { 
 private mediaplayer mp; 
 private lyricview lyricview; 
 private string path = "/sdcard/mp3/because of you.mp3"; 
 /** called when the activity is first created. */ 
 @override 
 public void oncreate(bundle savedinstancestate) { 
 super.oncreate(savedinstancestate); 
 setcontentview(r.layout.main); 
 lyricview = (lyricview) findviewbyid(r.id.audio_lrc); 
 mp = new mediaplayer(); 
 mp.reset(); 
 try { 
  mp.setdatasource(path); 
  mp.prepare(); 
 } catch (illegalargumentexception e) { 
  // todo auto-generated catch block 
  e.printstacktrace(); 
 } catch (illegalstateexception e) { 
  // todo auto-generated catch block 
  e.printstacktrace(); 
 } catch (ioexception e) { 
  // todo auto-generated catch block 
  e.printstacktrace(); 
 } 
 mp.start(); 
 new thread(new uiupdatethread()).start(); 
 } 
 class uiupdatethread implements runnable { 
 long time = 100; // 开始 的时间，不能为零，否则前面几句歌词没有显示出来 
 public void run() { 
  while (mp.isplaying()) { 
  long sleeptime = lyricview.updateindex(time); 
  time += sleeptime; 
  mhandler.post(mupdateresults); 
  if (sleeptime == -1) 
   return; 
  try { 
   thread.sleep(sleeptime); 
  } catch (interruptedexception e) { 
   // todo auto-generated catch block 
   e.printstacktrace(); 
  } 
  } 
 } 
 } 
 handler mhandler = new handler(); 
 runnable mupdateresults = new runnable() { 
 public void run() { 
  lyricview.invalidate(); // 更新视图 
 } 
 }; 
} 

整个project的源码。包括yoyoplayer的解析lyric部分代码。

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。